1. Technical Field
The disclosure relates generally to electronic test probes and, more particularly, to electronic test probes for testing integrated circuits (ICs).
2. Related Art
During testing, integrated circuit (IC) packages are removably mounted in sockets which in turn are mounted on a circuit substrate, commonly referred to as a device-under-test board, or DUT board. The sockets house individual electrical test probes for electrically connecting each terminal of a device to be tested to an individual circuit path on the DUT board. The DUT board is in turn electrically connected to computerized test equipment.
It is desirable to have a high integrity signal path from the test equipment to the device being tested and for the overall resistance of the signal path to be low and consistent. This is also true for each segment of the overall signal path—including the test probe housed in the test socket.
The electrical test probes can comprise electrically conductive metal components that are surface finished with an electrically noble metal such as gold or palladium cobalt. To assure the low and consistent resistance of the test probe, the metal components are precisely located in close proximity to each other, and the normal force between the components is kept high enough to keep the components in direct contact with each other and to break through any surface barriers that might be in place between the components.
It is desirable to have low and consistent resistance in electrical test probes. One way of achieving this is to ensure that electrical current flows from the sliding plunger to the barrel of the test probe with a minimum of contact resistance.
A need exists in the art for reliable, low contact resistance test probes and methods of making the same.